[Buppa]

Scratching my head......

89 YJ 2.5L 5spd - basically stock, 7ft Meyers plow w/E60 pump motor

Starts fine and runs good until....

step on the brake = shuts off.

turn on the lights = shuts off

turn signals = shuts off

hazards = shuts off

Prior to shutting off as above, high beam indicator and both turn signal lamps come on, and flicker after about 5 seconds.

Thoughts ???

Thanks in advance

[Luckyduck]

Sounds like something in the taillight circuit is shorting out the electrical system

[xeastend]

Chech the turn/stop bulbs,front and rear.Should be 1157.Double filament.If one is broken,could be touching the good filament and back feeding thru the electric system.
Sounds crazy,but I have seen that happen in a tractor trailer I used to drive

[Mazookie]

I thought my electrical was bad. Thats is the weirdest thing I have ever heard. Good luck getting it back up.
~Mazooks~

[Buppa]

Thanks for the thoughts gang....

I also thought maybe something in the tailights...somewhere....somehow....maybe....

I was also going to look at that mess of wiring at the very poorly located starter relay on the firewall....dunno why, but instinct is also pointing me that way.

I let you know what I find....

[sentinal02]

Originally Posted by Buppa

Thanks for the thoughts gang....

I also thought maybe something in the tailights...somewhere....somehow....maybe....

I was also going to look at that mess of wiring at the very poorly located starter relay on the firewall....dunno why, but instinct is also pointing me that way.

I let you know what I find....

the starter relay acts as the jump point for the rest of the electrical system. most of those wires you see coming off there are fusible links which power the rest of the jeep. i would try pulling fuses for the lights 1 at a time and see if the problem persists with the fuse in question removed. it might point you in the direction of the problem if you find one that stops the problem from happening when removed. removing the bulbs themselves one at a time might also be helpful.

the other question to answer is what's the method causing the jeep to stall. ie shorting the fuel pump, cutting power to the ecu, cutting power to the coil, etc. we know the actions that are causing the failure, but you still don't know the method.

[Buppa]

First, thanks for the replies !

Next: I pulled the fuse for stop, turn, tail, = no change - turn signal indicators and high beam indicators on kinda dim - spins but barely (if at all) fires.

Then I yanked the flashers - hazard & turn = same as above

Then the bulbs, 1 at a time = same as above

Then the headlight relay = no change, but... now I get the turn signal indicator lights, high beam indicator light, and brake idiot light on bright when I turn the key to on and / or start positions and it wil spin but not fire, or sometimes barely fires and then quits.

[yamaguy01]

Sounds like a nightmare! I'm no electrician but possibly there is something shorting out in your column since all those functions run through there and those wires are jam packed in there. Either way I wish you the best of luck, my '89 YJ had it's wiring problems of it's own when I bought it. Painless does have a YJ specific harness available now finally after all this time! I wish they had one several years ago when I was fighting with my wires.

Dave

[Classicboss1]

Check to make sure there is no rust on the grounding plate inside the tail lights. If they are real rusty you will lose some of the ground connection and cause all sorts of funky problems. Check all bulbs including any side marker lights too. I just replaced my tail lights due to all sorts of stuff going on and all my lights are working like new. both tail light grounding plates have to be bolted to the jeep for them to function just an FYI Good luck.

Dan

[Buppa]

Dan,
I did check the tail light plates the other day when I did the bulb removal experiment. All checked clean and tight. I had replaced both assemblies with new ones about a year ago, and they still looked good.

I pulled the headlight switch assembly out last night, and it does not look so good....couple of spots look overheated, and corroded. When I get a new one installed, I'll post an update.

Fingers crossed !

[Buppa]

Finally figured this thing out totally by accident, I might add....

I had tried everything suggested, plus a hundred things more, when yesterday, I've got it running...but not too well...idling kinda rough, and hard starting also.

I'm standing in front of it with my hand on the snowplow lift arm, and happened to wiggle it back and forth slightly. The engine suddenly starts running smoothly, until I wiggle it again, and the engine dies !!! WTF ( I'm thinking to myself ) Do I have a bad GROUND and not a SHORT somewhere ?????

I grab a set of jumper cables, and use one to go from the negative battery post to a spot I cleaned off on the frame. I start it up....hey that seemed a little...no, a lot better....turned over once or twice and fired right up, and ran smooth !!!

Hmmmm..... I shut it down, and I take the other cable and jump across the braided ground strap from engine block to firewall.

Start it up again.....same thing...one or two turns....fires right up, runs smooth.....but now......no more shut down when the lights are turned on, or you step on the brake, or any of the other stupid things it was doing before.

Seems I was not experiencing a short, but a loss of ground !!!!!

Lesson learned !!!!

Thanks to all for their input.....MUCH appreciated !!!

[Buppa]

So....replaced the ground strap - engine block to fire wall, and neg. battery cable.

Problem totally rectified...she's been running like a top for a couple of weeks, so that's the end of this fiasco !